10-acetamido-s-triazolo-(3,4-a)-isoquinolines

ABSTRACT

NOVEL S-TRIAZOL-(3,4-A)-ISOQUINOLINE COMPOUNDS ARE PREPARED BY METHODS ANALOGOUS TO KNOWN METHODS AND EXHIBIT ANTI-AGGRESSIVE ACTIVITY.

United States Patent O 3,814,711 10-ACETAM1DO-s-TRIAZOL0-[3,4-a]-.ISOQUINOIJNES Fernand G. F. Eloy, Rhode St. Genese, Belgium, and MortonE. Goldberg, Glen Rock, N.J., assignors to Mallinckrodt Chemical Works,St. Louis, M0. N Drawing. Filed July 26, 1971, Ser. No. 164,881 Int. Cl.C07d 33/56 US. Cl. 260-287 R 1 Claim ABSTRACT OF THE DISCLOSURE Novels-triazolo-[3,4-a]-isoquinoline compounds are prepared by methodsanalogous to known methods and exhibit anti-aggressive activity.

BACKGROUND OF THE INVENTION The present invention relates to thepharmaceutical field, and more particularly to methods andpharmaceutical compositions for treating mammals utilizing as activeagents certain novel organic heterocyclic compounds from the class knownas s-triazolo-[3,4-a]-isoquinolines.

The preparation of various s-triazolo-[3,4-a]-isoquinolines is disclosedby (1) S. Naqui et al., Indian J. Chem., 3, 162-4 (1965); (2) G. S.Sidhu etal., Jour. Heterocyclic Chem., 3, 158-164 (1966); (3) J. -E.Francis, US. Pat. 3,354,164 (1967); (4) H. K. Reimlinger et al., FrenchPat. 1,573,135 (1969) and (5) H. K. Reimlinger et al., Chem. Ber. 103,1960-1981 (1970).

No pharmaceutical compositions or utility are disclosed in references(1), (2), (4) and (5) cited above. Francis (3) discloses thatunsubstituted s-triazolo-[3,4-a]-isoquinoline and its 3-lower alkylderivatives are coronary vasodilators.

The invention is particularly concerned with certain novel compoundsuseful in selectively inhibiting aggressive behavior in mammals.

It is known that certain compounds exhibit a type of central nervoussystem activity characterized as antiaggressive activity. For example,it has been previously reported that benzquinamide, a central nervoussystem depressant (Merck Index, Eighth Ed., p. 136), and tetrabenazine,an antipsychotic agent (Merck Index, Eighth Ed., p. 1022) possess somedegree of antiaggressive activity.

It has been confirmed that lesions in the septal region of the forebrainin rats produces a striking'increase in emotional behavior. Brady etal., J. Comp. Physiol. Psychol. 46, 339 (1953) and Brady et al., J.Comp. Physiol, Psychol. 48, 412 (1955). This is accompanied by violentattack behavior in response to previously neutral stimuli (septal rats).The elfects of depressant compounds on this type of aggressive behaviorhave been reported, e.g., Hunt, NY. Acad. Sci., 67, 712 (1957), Randallet al., J. Pharmacol. exp. Ther. 129, 163 (1960) and Malick et al.,Arch. int. Pharmacodyn. 181, 459 (1969). In addition, it has been shown(Karli, C. R. Soc. Biol. 149, 2227 (1955) and Karli, Behaviour, 10, 81(1956)) that certain rats will readily attack and kill mice uponpresentation (killer rats). Here again, it has been demonstrated thatcertain antidepressants, stimulants and anti-histaminics selectivelyinhibit the muricidal (mouse killing) response in these rats (Horovitzet al., Life Sci. 4, 1909 (1965) and Horovitz et al., Int. J.Neuropharmacol. 5, 405 (1966)). So-called septal rats and killer ratsprocedures have thus been established to determine the inhibitory effectof test compounds on aggressive behavior (of. Goldberg, Arch. int.Pharmacodyn, 186, 287 (1970).

SUMMARY OF THE INVENTION Among the several objects of the invention maybe noted the provision of certain novels-triazolo-[3,4-a]-isoquinolines; the provision of such compounds whichexhibit anti-aggressive activity; and the provision of pharmaceuticalcompositions and methods for inhibiting aggressive behavior in asusceptible mammal, which compositions and methods utilize the novels-triazolo-[3,4-a]- isoquinolines as active agents. Other objects willbe in part apparent and in part pointed out hereinafter.

The present invention is thus directed to novels-triazolo-[3,4-a]-isoquinoline compounds from the group hereinafterspecifically set forth. The invention is also directed to a method ofinhibiting aggressive behavior in a susceptible mammal by administeringto said mammal an effective amount of such ans-triazolo-[3,4-a]-isoquinoline compound and to pharmaceuticalcompositions comprising such a compound and a pharmaceutical carrier.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In accordance with the presentinvention, it has now been found that certain novels-triazolo-[3,4-a]-isoquin0- line compounds exhibit anti-aggressiveactivity. The type and degree of anti-aggressive activity observed withs-triazolo-[3,4-a]-isoquinoline compounds is selective in nature and thepresence or absence of such activity, and its degree when present,appears to be quite sensitive to the position and type of substitutionon the basic s-triazolo- [3,4-a1-isoquinoline structure.

The novel s-triazolo-[3,4-a1-isoquinoline compounds of the inventionwhich have been found to possess antiaggressi-ve activity are:

6-chlorol O-acetamido-s-triazolo- [3 ,4-a] -isoquinoline3,6-dimethyl-s-triazolo-[3,4-a]-isoquinoline3-methyl-7,8,9-trimethoxy-s-triazolo-[3,4-a]-isoquinoline 7,8,9-trimethoxy-s-triazolo- [3 ,4-a] -isoquinoline 9-methyl-s-triazolo-[3 ,4-a] -isoquinoline 3-methyl-5-butyl-s-triazolo-[3,4-a]-isoquinoline5 buty1-s-triazolo- [3,4-a] -isoquinoline 3 (N-pyrrolidinyl)-9-methyl-s-triazolo- 3,4-a1-isoquinoline3-isobutyl-5,6-dihydro-s-triazolo-[3,4-a1-isoquinoline3-(N-pyrrolidinylmethyl)-5,6-dihydro-s-triazolo-[3,4-a]- isoquinolineand the pharmaceutically acceptible, nontoxic acid addition saltsthereof. Such addition salts may be derived from hydrochloric acid,hydrobromic acid, phosphoric acid, methanesulfonic acid and the like.

In general, the novel s-triazolo-[3,4-a1-isoquinoline compounds of theinvention may be prepared by the reaction of l-hydrazinoisoquinolinewith an acidic reagent as disclosed in H. K. Reimlinger et a1. FrenchPat. 1,573,135 (1969), either in the presence or absence of a solvent.As illustrated by the working examples hereinafter, many of thes-triazolo-[3,4-a1-isoquinolines of the invention may be prepareddirectly from the corresponding ringsubstituted hydrazinoisoquinolineand the specific acidic agent. In the case of the two5,6-dihydro-s-triazolo-[3,4- a]-isoquinoline compounds of the invention,these may be prepared by electrolytic or catalytic hydrogenation.

In further accordance with the invention, pharmaceutical compositionsand methods useful in inhibiting aggressive behavior in susceptiblemammals are provided the compositions comprising an aforementioneds-triazolo [3,4-aJ-isoquinoline compound and a pharmaceutical carrierwhich may be either liquid or solid material. These compositions may beadministered orally or parenterally in the usual pharmaceutical formsincluding capsules, tablets, solutions, suspensions and the like. Forexample,

the s-triazolo-[3,4-a]-isoquino1ine compound may be formulated withcarriers such as magnesium stearate and lactose and filled into gelatincapsules. Examples of other solid pharmaceutical carriers, such asfillers, binders and lubricants, include dibasic calcium phosphate,calcium sulfate dihydrate, microcrystalline cellulose, calcium carbonateand tale. The pharmaceutical compositions of the invention may also bein the form of sterile parenteral solutions with thes-triazolo-[3,4-a]-isoquinoline compound dissolved in a sterileparenteral solvent such as polyethylene glycol, propylene glycol, wateror mixtures of solvents or the compositions may be in the form ofsuspensions.

Where the s-triazolo-[3,4-a]-isoquinoline compound is water-insoluble,it is preferred that the compound be formulated into the pharmaceuticalcompositions of the invention in a micronized form, as by milling thecompound by conventional methods. More particularly, it is preferredthat the compound be micronized to a particle size of approximately 1-10microns.

The following examples illustrate the invention.

In each of Examples 1-l0, the indicated structure was confirmed byinfrared spectroscopy.

EXAMPLE 1 Preparation of 6-chloro-IO-acetamido-s-triazolo[3,4-a]-isoquinoline EXAMPLE 2 Preparation of 3,6-dimethyl-s-triazolo-[3,4-a1-isoquinoline 1-hydrazino-4-methylisoquinoline was dissolved in excessacetic acid and heated at reflux for 4 hours. Excess acid was removed invacuo and the residue was dissolved in chloroform and washed with sodiumcarbonate solution. Concentration of the organic extracts andrecrystallization of the residue from ethanol and cyclohexane providedthe product in a yield of 62%; M.P. 2l3214 C Calculated for 0 mm,: 0,73.07; H, 5.62; N, 21.31. Found: C, 73.12; H, 5.58; N, 21.69.

EXAMPLE 3 Preparation of 3-methyl-7,8,9 trimethoxy-s-triazolo-[3,4-a]-isoquinoline NHNH: I I s C)N crnooon m MeO MeO MeO Excess aceticacid and 1-hydrazino-5,6,7-trimethoxyisoquinoline were heated at refluxfor 4 hours. Excess acid was removed in vacuo and the residue wasdissolved in dichloromethane and washed with sodium carbonate solution.Concentration of the o ga ic layer a d re rystal- MeO MeO

4 lization from toluene provided the product in a yield of 60%; M.P.196198 C.

Calculated for C H N O C, 61.50; H, 5.50; N, 15.40. Found: C, 61.65; H,5.56; N, 15.32.

EXAMPLE 4 Preparation of 7 ,8,9-trimethoxy-s-triazolo-[3,4-a1]-isoquinoline N-N NHNH,

MeO

MeO

EXAMPLE 5 Preparation of 9-methyl-s-triazolo-[3,4-a1-isoquinoline NHNH:

is" (as A solution of 1-hydrazino-7-methylisoquinoline (11 g.) intriethylorthoformate (70 ml.) was heated at reflux for 3 hours. Afterremoval of the solvent, the residue was Washed with sodium carbonatesolution, treated with decolorizing carbon and recrystallized fromtoluene to provide the product in a yield of 44%; M.P. 201-202 C.

Calculated for C H N C, 72.11; H, 4.95; N, 22.94. Found: C, 72.05; H,5.00; N, 22.88.

EXAMPLE 6 Preparation of 3-methyl-S-butyl-s-triazolo-[3,4-a]isoquinoline N--N NHNH, I I A N N C cmooorr A solution of3-butyl-l-hydrazinoisoquinoline in excess acetic acid was allowed toreflux. Removal of the excess acid, washing with sodium carbonatesolution and recrystallization from cyclohexane-benzene (50/50) providedthe product in a yield of 65%; M.P. 144-145" C.

Calculated for C15H17N3: C, 75.30; H, 7.11; N, 17.55. Found: C, 75.10;H, 7.30; N, 17.95.

EXAMPLE 7 Preparation of S-butyl-s-triazolo-[3,4-a1-isoquinoline NHNH:

N-N I 1 ON HC(OEt); N

Bu Bu A solution of 3-butyl-l-hydrazinoisoquinoline in triethylorthoformate was allowed to reflux for 3 hours. On cooling, the productprecipitated and it was collected y filtration. Re y allization fr mbenzene-petroleum ether.(50/50) provided the product in a yield of 55%;M.P. 125-126 C. I v

Calculated for C14II15N3: C, 74.60; H, 6.66; N, 18.65. Found: C, 74.29;H, 6.54; N, 18.85.

EXAMPLE 8 Preparation of3-(N-pyrrolidinylmethyl)-9-methyl-s-triazolo-[3,4-a]-isoquinolinedihydrochloride l J-CH1 1 o1on.o o 01 N 2) I J A solution of equimolaramounts of chloroacetyl chloride and 1-hydrazino-7-methylisoquinoline innitromethane was stirred for one hour and filtered. The filter cake washeated for 8 hours with pyrrolidine and the reaction mixture wassuspended in water. The aqueous suspension was extracted withdichloromethane, and the organic layer was concentrated. The concentratewas treated with methanolic hydrogen chloride and the product wasrecrystallized from ethanol-ether in a yield of 40%; M.P. 252-254 C.

Calculated for C H N -2HCzl C, 56.55; H, 5.90; N, 16.50; Cl, 20.98.Found: C, 56.31; H, 6.16; N, 16.40;

EXAMPLE 9 Preparation of 3-isobutyl-5,6-dihydro-s-triazolo-[3,4-a]-isoquinoline 3-isobutyl-s-triazolo-[3,4-a]-isoquinoline (2.25g., 10 mmol.), tetramethylammonium chloride (5.5 g.) and 50 ml. methanolwere placed in the cathode of an electrochemical cell, and water (2ml.), allyl alcohol (3 ml.) and methanol (20 ml.) were placed at theanode. The reduction was carried out at a constant voltage of volts andthe current varied from 0.1 to 0.41 amperes. On completion of thereduction, the methanolic layer was concentrated; water was added, andthe solution was extracted with benzene. Evaporation of the benzeneextracts provided a solid, which was recrystallized from ether toprovide the product, 2.0 g. (87%) as white needles; M.P. 107108 C.

Calculated for C H N C, 73.97; H, 7.54; N, 18.49. Found: C, 73.92; H,7.12; N, 18.64.

EXAMPLE Preparation of 3-(N-pyrrolidinylmethyl)-s-triazolo- [3,4-a]-isoquinoline dihydrochloride N HNH:

N \J H Two separate batches of3-(N-pyrrolidinylmethyD-striazolo-[3,4-a]-isoquinoline (20 mmol.),tetramethylammonium chloride mmol.) in methanol were placed in thecathode of an electrochemical cell and tetramethylammoniu-m chloride (2g.), allyl alcohol (3 ml.) and methanol (20 ml.) were placed in theanode compartment. A voltage of 5 volts was applied and the currentvaried from 0.6 to 0.54 amperes. The methanolic solutions wereevaporated; the residue was treated with water and the mixture wasextracted into dichloromethane. The organic extracts were combined andconcentrated, and the residues were dissolved in 5 ml. of carbontetrachloride. On cooling, crystals were deposited and collected and thefiltrates were chromatographed on acidic alumina followed by silica gel.The crystals and the chromatographed material were dissolved in methanoland treated with methanolic hydrogen chloride. The product was collectedby filtration; M.P. (free base) 2530 C., M.P. (dihydrochloride salt)2l1-238 C. (dec.). 1

In the following animal studies, male hooded rats of the Long-Evansstrain, weighing between 200 and 300 grams, and male albino mice,weighing approximately 20 grams, were used as subjects. They werepermitted food and water ad libitum except during drug studies andduring the period in which killer rats were selected.

EXAMPLE 11 The anti-aggressive activity of representative compounds ofthe invention was determined using the following septal rats testprocedure.

Bilateral electrolytic lesioning, utilizing anodal DC current, of theseptal area was performed under pentobarbital anesthesia. The animalswere stereotaxically lesioned, using a slight modification of the methodof Stark and Henderson (Int. H. NeuropharmacoL, 5, 385 (1966)), in whicha current intensity of 7 milliamperes was delivered for 15 seconds toeach septal region. All animals were given penicillin prophylactically,and were initially tested 3 to 6 days after lesioning. The Konig andKlippel atlas (cf. The Rat Brain, Williams & Wilkins Co., Baltimore,.Md., 19 63) was utilized for histological verification of lesion sitesin selected animals. A scoring system was used which measured only theaggressiveness component of the septal syndrome. The animals were tailrestrained and evaluated before and 60 minutes after the intraperitonealinjection (I.P.) or oral administration of the compounds tested. Twoinanimate objects, a pencil and a glove, were offered and reactions weregraded as: 0=indifference to either stimulus, l =nibbling of one or bothobjects, 2=voracious attack of 1 object, 3==voracious attack of bothobjects. Only rats which exhibited a score of 3 prior to injection of atest compound were used, and animals which showed a 0 or 1 score atretest (60 minutes post injection) were considered blocked. The ED valuewas obtained for each compound tested and is defined as that dose whichresults in a score of 0 or 1 in 50% of the animals tested. The followingresults were obtained:

triazolo-[3,4-a]-lsoquinollne hydrochloride 1 Approximately.

7 EXAMPLE 12 The anti-aggressive activity of 3,6-dimethyl-s -itriaaolo-[3,4-a]-isoquinoline was determined using the following killer rats testprocedure.

The animals were housed individually for approximately 6 weeks andmaintained on a restricted food intake of 15 grams per day of solid foodand water ad libitum. After isolation, the rats were tested for theirmouse-killing response and only those animals which killed mice within 2minutes after presentation on 3 consecutive days were used. The selectedanimals were tested twice prior to treatment and at 30, 60, 120, 180 and240 minutes after intraperitoneal injection of the test compound. The EDwas obtained and is defined as that dose which blocks attacks in 50% ofthe animals tested. The ED for3,6-dimethyl-s-triazolo-[3,4-a]-isoquinoline was found to be 29.5mg./kg.

EXAMPLE 13 The anti-aggressive activity of 9-methyl-s-triazolo-[3,4-a1-isoquinoline was determined using the following isolatedfighting mice" procedure.

The test animals were male mice which had been isolated in a cage forthree weeks. The mice were aggressive and would attack within 5 minutesa non-isolated male mouse placed in its cage. After interaction of 5minutes, the second mouse is removed. If no fighting occurred duringthis interval, the isolated mouse was considered to have been renderednon-aggressive. The ED was obtained and is defined as that dose of thetest compound (administered orally or by intraperitoneal injection)which renders 50% of the animals tested non-aggressive. The ED for9-methyl-s-triazolo-[3,4-a]-isoquinoline was found to be 24.5 mg./kg.for intraperitoneal injection and 36 mg./ kg. for oral administration.

8 In view" ofthe'above; it will besee'n that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above methods and compositionswithout departing from the scope of the invention, it is intended thatall matter contained in the above description shall be interpreted asillustrative and not in a limiting sense.

What is claimed is:

1. 6 chloro 10 acetamido s'- triazolo-[3,4-a]-isoquinoline.

References Cited OTHER REFERENCES Sid Hu et al.: Jour. Hetero. Chem.,vol. 3, pp. 158- Goldberg et al.: Chem. Abstn, vol. 74, col. 11704m(article dated February 1970).

DONALD G. DAUS, Primary Examiner US. Cl. X.R.

mg I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,81 4, 711 Rated June 4 1 9 74 Inventor(s) Fernand G. F. Eloy and MortonE. Goldberg It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

F Ihe title, reading "lO-Acetamido-g-Triazolm-E3,4-g1-Isoquin0lras'should read 6-Chloro-10-Acetamido Triazo1o-E3, b-g j Isoquinoline Signedand sealed this 29th day of October 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. I C. MARSHALL DANN Attesting Officer I Commissionerof Patents

